Firstly, they misrepresent my views on graphite, which I point out is a “perceived fire risk” I was never suggesting it will catch fire if you put a match to it. I make this point repeatedly in the comments above, I even added a little section to chapter 6 to describe the two sides of the fire risk argument and clarify my position.
http://daryanenergyblog.wordpress.com/ca/part-6_htgr/6-4-3-fire-risk-and-mitigation/But the fact opaque minds of BH and CB seem unable to absorb any information that contradicts their position. They also seem to have no idea about the concept of scientific uncertainty or the precautionary principle or the most basic concepts of how passive safety is guaranteed. These would require “some” action be taken on this issue.
http://daryanenergyblog.wordpress.com/2011/07/31/the-precautionary-principle/Indeed they compound there mistake by then misunderstanding why graphite is used in Class D fire extinguishers (for liquid metals!). Oh, and later on BH suggests you can use jet fuel to put out fires (yes really!). I’ll let the reader assess the practicalities of that!

I could go thro this line by line but there’s no point, all they succeed in doing is demonstrating their own ignorance of the facts and inability to absorb any information that contradicts the LFTR gospel.

“the author counters his own point” no I don’t! I was just trying to give a fair and balanced assessment, but don’t let facts get in the way of a good hatchet job.

“low vapour pressure” The pressurization issue is a bit of red herring, the major materials stumbling block is the issue of the combination of corrosive attack under temperature, with a bit of radiation thrown in for good measure. The low vapour pressure solves some problems but creates others due to the difficult it creates in getting decent thermal efficiency and that it increases the risk of intrusion of outside air (unless you surround the reactor in a inert gas Caladaria, but that would be pricy and “complicate things”).

“MS in solar energy” – BH doesn’t seem to understand that solar thermal plants are a different kettle of fish, different salt mixtures, temperatures and pressures and most importantly no radioactive thorium suspended within.

BH then goes into a detour unrelated to the article, but which came up in discussion, regarding his fantasy’s of removing uranium from sea water. This has been refuted by several peer reviewed papers (Barti 2007 and Barti etal 2011, Dittmar 2011) claiming that such a process would likely yield less energy back than it returned. Such proposals also ignore certain practicalities. Barti suggests http://www.theoildrum.com/node/4558 that we would have to cover the whole of North Sea with Uranium adsorption structures in order to get enough uranium for just 16% of the present world’s electric power production. Dittmar suggests http://greatchange.org/ov-dittmar,nuclear_option_ASPO.pdf that you would need to capture and filter the flow of 5 times that of the Rhine river to run just one nuclear power station, so clearly impractical! Of course building a dam and using such a flow for hydroelectricity would yield substantially more energy as would covering a small patch of the North Sea in wave energy machines. BH seems unable to absorb these facts. It was repeatedly pointed out to him in this discussion above and Barti and others in the blog he links to as well. BH seems to declare “victory” of sorts here on the fact that Barti gave up trying to get the message across (I don’t blame him!). Indeed if you view that blog string you’ll see even several pro-nuke bloggers running out of patience with BH one describing him as a “propagandist” http://europe.theoildrum.com/node/4558#comment-415499. He seems to think that just because everyone else left him mumbling to himself that counts as victory.

“Publishing a quip that you know is misleading and prejudicial is unethical”…no it’s a quip, an amusing comment, you know? A joke! I know Americans lack our British sense of humour, but how old are you? grow up!

He then goes into a discussion about the CPP, making various stabs at it, that basically just confirms my worst fears (yet again) the LFTR fans have no idea how efficient this system will be, how to design it or what its implications to reactor operations are. Later he very wisely jettisons the idea, at least temporarily until the reactor is proven.

Indeed as part of this effort he also throws out Thorium, Air based cooling, the CPP, open cycle operation, small exclusion zones, baby, bath water and pram go flying over the side in a desperate fit of back peddling. Of course this puts his post in direct contradiction to the infamous wired mag article (which specifically highlighted the lack of large exclusion zones and Thorium as key positives of the MSR). Shall they be calling Wired asking for a retraction of these points? or indeed alter they’re own websites and all of those LFTR videos doing the rounds (and at this rate if BH keeps it up those 2 hr vids will be down to “hello” and “goodbye”) to reflect this new position? Well of course not! Who said we should let facts getting the way of a good techno fantasy!

Finally BH arrives at a point with a reactor design, not far removed from the Micro-fuji proposal, one that I acknowledged (8.12) had an air of plausibility surrounding it (of course he ignores this fact also). However BH neglects to point out the crucial arguments I made regarding cost. It’s clear that the MF will be rather expensive, far more so than any other reactor prototype of recent years and its difficult to avoid the argument that a follow on commercial unit will still be more expensive than existing LWR or HTGR technology. Given that we jettisoned all of the bits of the MSR that gave it its unique selling point, why would anyone invest in such an endeavor? You want cheap nuclear (relatively speaking!)? Use LWR’s. Want to burn Thorium? Use HTGR’s. Want cheap(ish) energy with no nuclear waste? We have renewables. We could add back in those bits of the MSR BH threw away, but that would greatly increase our R&D costs as well as the development time scale and increase the risk of the whole project failing.

He tries to counter my point about load cycling by quoting figures from the, as of yet untested, AP1000. He ignores the fact that the grid can see sudden changes in the order of GW’s per second, I believe it hits about a 2-4 GW swing (in a few seconds) here in the UK when a popular soap ends. While I acknowledge that newer reactors like the AP1000 should offer much greater flexibility than past reactors (but that’s unproven as no AP1000 reactor has yet been commissioned), they certainly don’t close the circle and a LFTR would be a very different beast (if he’d bothered to read my article), so it’s not a relevant comparison.

Also BH tries to disprove the well known toxicity of fluorine. He presents figures showing that fluorine (it doesn’t specify in which form) has a lethal dose (to a rat) of 300 mg (sounds pretty deadly to me!) and Chlorine at 4 times higher, with him then claiming that in fact it’s the other way around (i.e. the numbers suggest that Flourine is more deadly as it has a smaller lethal dose)…?…Also I would note that there’s a very big difference between both substances in various chemical forms or in the form of an easily inhaled gas, hence why people don’t keel over when brushing ones teeth!

I could go on, but its pointless. As I’ve shown, many LFTR fans see the world thro rose tinted glasses. They only absorb facts that support their technofantasy, can’t see the contradictions in they’re own arguments and assume any criticism is the work of Satan and it must be exorcised at once least the flock here of such heresy. Anyone who criticizes there views is either misinformed (even if he’s a respected nuclear scientist) or “one of them”…which brings us onto…
…Ad Homein comments? Pot calling the kettle black me thinks. Its strange that this is the opener from CB last time around (i.e. claim that I’m baised) and that the primary tool of LFTR fans is to attack the person and not the facts (as I think we’ve learnt most of them are “Rank amateurs”). Look at this rebuttal of the ecologist magazine article here: http://energyfromthorium.com/rees-article-rebuttal/. Almost all the various “rebuttals” of my critique online soon lurch into the form of personal attacks that question my credentials.

I intend to post my own response to Ryan's comments, but Bill has beaten me to the punch.

“Firstly, they misrepresent my views on graphite, which I point out is a “perceived fire risk” I was never suggesting it will catch fire if you put a match to it.”

A small sliver of coal can be ignited with a match.

“we cannot conclusively conclude that there is no fire risk (as some mistakenly do), particularly given the evidence from Chernobyl.”

The Chernobyl reactor is as different from an MSR as the F-104 Starfighter is different from a Boeing 747. If someone used the F-104 accident rate as a reason to prevent the R&D of new improved airliners would you consider that a good argument?

“any ideas we have about building HTGR’s without containment domes”

First, no nuclear power plants are going to be built without containment. Second, chapter 8 is about MSR's, which have liquid fuel, making the fire analysis much different than for a solid fueled HTGR.

“BH suggests you can use jet fuel to put out fires (yes really!). I’ll let the reader assess the practicalities of that!”

Actually I showed that the temperature of burning jet fuel is lower than the normal operating temperature of an MSR, so jet fuel could be used to cool a MSR. Furthermore if you somehow induced a pile of nuclear grade graphite to burn, spraying it with jet fuel would lower its temperature well below the ignition temperature, putting out the graphite fire, and once all the residual jet fuel burns up the fire would stay out if there is no other source of heat to re-raise the temperature of the graphite.

I never claimed that real MSR plants will keep large storage tanks of jet fuel for use in response to a fire. The point of the example is to illustrate the fact that machines designed for very high temperature operation are easier to cool than machines made of low temperature materials. R avoids addressing this key technical point by deflecting with ridicule and misdirection.

“the major materials stumbling block is the issue of the combination of corrosive attack under temperature, with a bit of radiation thrown in for good measure.”

Which is why I support building several small experimental plants of promising designs using the best materials available to get the needed performance data.

“The low vapour pressure solves some problems but creates others due to the difficult it creates in getting decent thermal efficiency and that it increases the risk of intrusion of outside air”

Here R is just making stuff up. If the salt had a lower boiling point it would have to be pressurized and that would somehow raise thermal efficiency? Nonsense.

“BH doesn’t seem to understand that solar thermal plants are a different kettle of fish”

I understand that solar thermal plants will be very large, expensive, use large quantities of land, concrete, steel and salt, and have only a few hours of storage, with a limited capacity factor, especially during periods of bad weather. But my recommendation, R’s, is to push R&D in all potential sources of energy, including solar, as hard as possible.

http://www.theoildrum.com/node/7275#comment-755200

“BH then goes into a detour unrelated to the article, but which came up in discussion, regarding his fantasy’s of removing uranium from sea water.”

No doubt in 1902 some people were chiding the Wright Brothers for pursuing their fantasy of flight.

“Dittmar suggests http://greatchange.org/ov-dittmar,nuclear_option_ASPO.pdf that you would need to capture and filter the flow of 5 times that of the Rhine river to run just one nuclear power station, so clearly impractical!”

Dittmar could prove that the tuna industry is uneconomical by calculating how much sea water you would have to pump through a tuna extraction plant to fill a 5 ounce can. Obviously a real uranium extraction process would take advantage of ocean currents. Dittmar’s predictions have proven largely wrong so far.

“Barti suggests http://www.theoildrum.com/node/4558 that we would have to cover the whole of North Sea with Uranium adsorption structures in order to get enough uranium for just 16% of the present world’s electric power production.”

As I said before, seawater uranium does not have to supply all our uranium to guarantee a price under $200 per pound, it only has to replace the conventional portion that is over that price, which is zero in the foreseeable future.

More importantly, our pre Model T reactors only split about 1% of the uranium atoms mined to fuel them. A fast Breeder reactor would only need about six pounds of uranium per day. It could get that from the sea water used to cool its condenser.

“we’re not “destroying” radioactive material in a reactor, we’re merely transmuting it from one form to another and were still left with a large pile of “nasty stuff” sitting in a storage container which we now have to either re-bury or baby sit for a few millennia.
So all in all I’d argue uranium mining causes as many (if not more) problems than it solves.”

Show us your references and calculations, deaths, brain damage, respiratory illness for uranium vs. fossil fuel, or you could study this report.

““publishing a quip that you know is misleading and prejudicial is unethical”…no it’s a quip, an amusing comment, you know?

What other forms of disinformation do you believe are ethical?

“It’s clear that the MF will be rather expensive, far more so than any other reactor prototype of recent years and its difficult to avoid the argument that a follow on commercial unit will still be more expensive than existing LWR or HTGR technology.”

The first handful of Chevy Volt’s cost GM several millions of dollars, and the first MSR's will cost more than conventional plants. What will #100 cost? What will #1000 cost?

Given their compact size and reduced material requirements factory mass production of major components and modules becomes possible leading to big cost and time savings.

“He tries to counter my point about load cycling by quoting figures from the, as of yet untested, AP1000. He ignores the fact that the grid can see sudden changes in the order of GW’s per second, I believe it hits about a 2-4 GW swing (in a few seconds) here in the UK when a popular soap ends.”

And what is that as a percentage of total power? Split that 2-4 GW between hundreds of power plants and it is not a problem. How do you think they handle it now?

“While I acknowledge that newer reactors like the AP1000 should offer much greater flexibility than past reactors (but that’s unproven as no AP1000 reactor has yet been commissioned), they certainly don’t close the circle and a LFTR would be a very different beast (if he’d bothered to read my article), so it’s not a relevant comparison.”

Actually, I cited the AP 1000 performance in response to the authors claim that “existing nuclear stations are capable of some level of power cycling anyway just not much!”

When Boeing and Airbus design a new aircraft, they usually perform within a few percent of the design point by the end of the development process. Does R suggest that the AP 1000 design is so slipshod that it could be off by a large margin?

It is interesting that R can draw damming conclusions about future MSR's based on the totally different 60 year old Windscale reactor design, but the AP 1000 is off limits.

The most important thing is that for the first few decades MSR's will be run continuously at 100% because their fuel cost will be lower than any fossil plant and lower than the fuel cost for most other nuclear plant designs. MSR's will not have to load follow until the grid is almost all nuclear powered.

“BH tries to disprove the well known toxicity of fluorine. He presents figures showing that fluorine (it doesn’t specify in which form) has a lethal dose (to a rat) of 290 mg”

Here is a cut and paste of the section R is referring to;

{ “Fluorine gas is extremely toxic (several times more deadly than chlorine”

Toxicity Data, Fluorine
LC50 inhal (rat)
185 ppm (300 mg/m3; 1 h)

Toxicity Data, Chlorine
LC50 inhal (rat)
293 ppm (879 mg/m3; 1 h)

http://www.nap.edu/openbook.php?record_id=4911&page=320

By volume fluorine is less than twice as toxic as chlorine. The U.S. consumes ten billion kg of chlorine each year; enough to kill every man woman and child in the U.S. every 45 minutes. Essentially all of that is manufactured and consumed under conditions less secure than those inside a reactor containment building.}

R claims it does not specify the form, but anyone familiar with toxicity data would know it is for elemental gas. R claims I said the lethal dose is 290 mg, but as you see, the units are mg/m3, and the number is 300.

R goes on to say;

“(sounds pretty deadly to me!) and Chlorine at 4 times higher, with him then claiming that in fact it’s the other way around”

So lets do the math for R; 293/185 = 1.58 which is less than 2 by VOLUME as I specified.

R tries to prove me wrong by doing a MASS calculation, but he gets that wrong too. 879/300 = 2.9 which is less than 4 and less than “several times”.

R’s focus on insults and silliness, his failure to engage on the important points and his amazingly high error rate shows the weakness of his position. Here are key questions and issues from my review comment that he has not addressed.

1. Our cheapest fossil fuel is coal. To generate an 80 year lifetime supply of electricity for one person in the U.S. with coal we burn 1,140,000 pounds of coal, producing 2,440,000 pounds of CO2 and thousands of pounds of toxic waste, much of it released into the atmosphere. Lifetime fuel cost with coal is $34,000, $424/year.

The simplest uranium burning MSR will need about 12 pounds of uranium to make a lifetime supply of electricity. What would the price of uranium have to be to make MSR fuel more expensive than coal per kWh?

LFTR will need six ounces of thorium to make a lifetime supply of electricity. What would the price of thorium have to be to make LFTR fuel more expensive than coal per kWh?

2. MSR's can be designed to operate without graphite. Do you support R&D of those designs?

3. The Windscale reactor had large fans blowing air through the core. How could a large flow of air pass through a MSR reactor vessel?

3a. What is the driving source of pressure gradient?

3b. How are the required holes created in the reactor vessel and containment walls?

3c. At Windscale and Chernobyl the solid fuel, moving air and graphite were in direct contact. In a MSR, the graphite is normally submerged in salt. Can graphite burn while submerged in salt?

3d. When solid fuel melts it can release a large burst of volatile fission products acumulated over a period of months or years. MSR's do not accumulate volatile fission products.

Do you acknowledge that MSR's will not contain a large mass of volatile fission products that can be released in an accident? If you disagree, what is the concentration, chemical composition, melting point, boiling point of the fission products that would be problematic in a MSR accident? Compare those numbers with the numbers for solid fuel reactors. Why don’t these highly volatile compounds come out of solution during Normal operation?

3e. If the graphite is exposed to air, most fission products are below the liquid line in a chemical form that is stable at very high temperature. How would the graphite burning in air volatilize a large quantity of low volatility fission product compounds in the salt below the fire or in a remote tank?

4. The only nuclear accidents to release large quantities of fission products are those where a direct path to the atmosphere is provided by design or by explosion. MSR's have continuous online refueling. There is only enough reactivity for normal operation. I do not know of any way to make an MSR explode. Do you, explain the mechanism in detail?

5. It is interesting that out of hundreds of fission products, only a few of the most volatile constitute most of the risk in solid fuel reactors.

Cesium is by far the most problematic long term fission product in an accident. It melts at 28C, the boiling point is 671 C. When a cesium atom is produced in a MSR it immediately hooks up with a fluorine atom to make cesium fluoride, melting point 682C, boiling point 1251 C, so it has much lower volatility resulting in greatly reduced emissions under accident conditions. Very little cesium will be released in a MSR accident. Provide detailed mechanism if you disagree?

By the way R. I am sure you can post your comments on Charles Barton’s blog, he does not engage in censorship as you do.

Apology to Some CommentersAn increasing number of Nuclear Green comments get classified as junk and shuttled off to some Google simi-limbo. When I attempt to retrieve them, they all too frequently disappear completely. My apology to my commenters. I do not censor comments unless they are in bad taste, but on the internet bad things inadvertently happen.